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At least 847 records · Page 47Linked to original sources
PubMed2003

WebFEATURE: An interactive web tool for identifying and visualizing functional sites on macromolecular structures.

WebFEATURE (http://feature.stanford.edu/webfeature/) is a web-accessible structural analysis tool that allows users to scan query structures for functional sites in both proteins and nucleic acids. WebFEATURE is the public interface to the scanning algorithm of the FEATURE package, a supervised learning algorithm for creating and identifying 3D, physicochemical motifs in molecular structures. Given an input structure or Protein Data Bank identifier (PDB ID), and a statistical model of a functional site, WebFEATURE will return rank-scored 'hits' in 3D space that identify regions in the structure where similar distributions of physicochemical properties occur relative to the site model. Users can visualize and interactively manipulate scored hits and the query structure in web browsers that support the Chime plug-in. Alternatively, results can be downloaded and visualized through other freely available molecular modeling tools, like RasMol, PyMOL and Chimera. A major application of WebFEATURE is in rapid annotation of function to structures in the context of structural genomics.

Algorithms↗
PubMed1993

Assessing visual function in the older driver.

It is likely that some older adults will have to be restricted from driving because of serious and irreversible deterioration in skills crucial to driving, due to vision impairment, visual attention deficits, and decreased cognitive status; however many older adults with driving difficulties can improve their driving skills or reduce their crash risk through education or training programs. Research to evaluate interventions such as those previously mentioned has high priority, given society's need to maintain the mobility and personal independence of older adults without sacrificing safety concerns.

Accidents, Traffic↗
PubMed1997

Visual functions in aphakia after secondary intraocular lens implantation.

21 aphakic eyes of 21 patients corrected by glasses (A-G) were examined 1 and 6 months before and after secondary intraocular lens implantation (SILI). Visual acuity (VA) was tested using Snellen chart and computerized method with Landolt rings (CL). Contrast sensitivity (CS) was measured using computerized Contrast sensitivity system 8010 in spatial frequencies from 0.74 to 29.55 c/deg. Preoperative best corrected VA (BCVA) in A-G eyes was significantly lower in comparison with control group of the same age only using computerized method with Landolt rings. A reduction of BCVA by both methods at 1 month and its return to original values after 6 months were noted. Significantly lower values of CS were found in A-G patients before SILI compared to the control group of the same median age in spatial frequencies from 3.69 to 29.55 c/deg. After 1 and 6 months the values stayed on the preoperative level, except the frequency 29.55 c/deg, which increased significantly (p < 0.01) 6 months after SILI.

Aged↗
PubMedDate not supplied

[Human visual functions during mild vestibular exposures].

Human experiments have shown that after mild stimulation of semi-circular receptors, which induces no motion sickness symptoms, the time of recovery of the central vision acuity shortens and after stimulation of otolith receptors tends to increase. Thresholds of color discrimination as applied to the red, green and violet colours as well as the course of back adaptation after mild stimulation of otolith receptors remain unchanged. The time of appearance of the Purkinje phenomenon after stimulation of receptors of semi-circular canals often remains unaltered and sometimes increases. It is assumed that the visual fixation of objects occurring with the time deficiency as related to the object display is accompanied by a compensatory-adaptive increase in the resolution capacity of the visual system.

Adult↗
PubMed2005

Pharmacological and rAAV gene therapy rescue of visual functions in a blind mouse model of Leber congenital amaurosis.

BACKGROUND: Leber congenital amaurosis (LCA), a heterogeneous early-onset retinal dystrophy, accounts for approximately 15% of inherited congenital blindness. One cause of LCA is loss of the enzyme lecithin:retinol acyl transferase (LRAT), which is required for regeneration of the visual photopigment in the retina. METHODS AND FINDINGS: An animal model of LCA, the Lrat-/- mouse, recapitulates clinical features of the human disease. Here, we report that two interventions--intraocular gene therapy and oral pharmacologic treatment with novel retinoid compounds--each restore retinal function to Lrat-/- mice. Gene therapy using intraocular injection of recombinant adeno-associated virus carrying the Lrat gene successfully restored electroretinographic responses to approximately 50% of wild-type levels (p < 0.05 versus wild-type and knockout controls), and pupillary light responses (PLRs) of Lrat-/- mice increased approximately 2.5 log units (p < 0.05). Pharmacological intervention with orally administered pro-drugs 9-cis-retinyl acetate and 9-cis-retinyl succinate (which chemically bypass the LRAT-catalyzed step in chromophore regeneration) also caused long-lasting restoration of retinal function in LRAT-deficient mice and increased ERG response from approximately 5% of wild-type levels in Lrat-/- mice to approximately 50% of wild-type levels in treated Lrat-/- mice (p < 0.05 versus wild-type and knockout controls). The interventions produced markedly increased levels of visual pigment from undetectable levels to 600 pmoles per eye in retinoid treated mice, and approximately 1,000-fold improvements in PLR and electroretinogram sensitivity. The techniques were complementary when combined. CONCLUSION: Intraocular gene therapy and pharmacologic bypass provide highly effective and complementary means for restoring retinal function in this animal model of human hereditary blindness. These complementary methods offer hope of developing treatment to restore vision in humans with certain forms of hereditary congenital blindness.

Acyltransferases↗
PubMed1998

The effect of nimodipine, a centrally active calcium antagonist, on visual function and mascular blood flow in patients with normal-tension glaucoma and control subjects.

PURPOSE: This study was performed to evaluate the effect of nimodipine, a centrally active calcium channel antagonist on automated Humphrey visual fields, Farnsworth-Munsell 100 (FM-100) hue color vision testing, and macular blood flow (blue field entoptic simulation technique) in patients with normal-tension glaucoma (NTG) and control subjects. METHODS: Thirteen patients with NTG and thirteen age- and sex-matched control subjects were studied in a prospective, placebo-controlled, double-masked, crossover protocol. On each of the two study dates, testing was performed at baseline and 90 minutes after administration of either two 30-mg nimodipine capsules or two identical appearing placebo capsules. Blood pressure and pulse were monitored throughout the study. RESULTS: Nimodipine administration resulted in a performance corrected improvement in Humphrey visual field mean deviation (patients with NTG and control subjects), corrected pattern standard deviation (patients with NTG), and macular sensitivity (the average of the foveal threshold and the four most central points of the visual field; patients with NTG). The FM-100 hue error scores significantly decreased after administration of nimodipine in patients with NTG and control subjects compared with baseline. There were no significant differences in baseline leukocyte velocity or density between patients with NTG and control subjects; no significant changes in leukocyte velocity or density were noted after administration of nimodipine in either group. CONCLUSION: Nimodipine caused a significant performance corrected improvement in visual field testing and a significant improvement in color vision. Nimodipine did not alter macular hemodynamics as measured using the blue field entoptic simulation technique, although results were hampered by high variability, particularly in the leukocyte density measurements.

Aged↗
PubMed1995

The Glenn A. Fry Award Lecture. Early losses of visual function in glaucoma.

Getting back to the questions raised by Dr. Enoch 12 years ago, I believe that we have made significant progress in the early psychophysical detection of glaucoma and that we are either on the right track or considerably closer to it. The continuing progress in conventional automated perimetry has improved the overall quality of visual field testing in the ophthalmic community, as well as providing standardization and state-of-the-art analysis procedures for everyone. We have certainly not solved the problem of early detection of glaucoma, but we now have more sensitive procedures that are available for existing clinical instrumentation. SWAP has clearly shown that it is able to detect glaucomatous losses several years before they are evident by conventional automated perimetry, and results from the other test procedures mentioned earlier are also very encouraging. Thus, although we may not yet have the pot of gold, we have been able to pick up a few valuable nuggets along the way. This leads me to believe that the current approaches are on the right track. However, Dr. Enoch's message should also serve to remind us that there are few panaceas for early detection of functional loss in glaucoma. Our progress to date has been influenced by our greater understanding of the properties of visual mechanisms and the pathophysiology of glaucoma. It has also been driven by clever and innovative approaches and new test procedures, as well as advances in technology. However, it has also been based on a considerable amount of research effort in the form of long-term prospective longitudinal studies of large populations of normal observers, patients with various stages of glaucomatous damage, and patients at risk of developing glaucoma. Answers to all of the issues pertaining to the ultimate clinical value of psychophysical procedures for early detection of glaucoma do not come quickly, but they are of vital importance to ocular health care. I hope that my brief discussion of new developments in psychophysical detection of glaucoma has convinced you that significant progress has been made, and that some of you will be motivated to join in this important research endeavor.

Awards and Prizes↗
PubMed1992

Assessment of visual function in autistic children.

Children with autism demonstrate "atypical" gaze or social "looking" and frequently manifest such sterotypies as eye pressing, hand flicking, and light gazing. This study's purpose was to evaluate autistic children for visual dysfunction that may be related to the manifested visual signs and symptoms. Thirty-four autistic children, ages 2 to 11 years (median age = 7 years, 6 months) were evaluated for ocular alignment, refractive error, visual acuity, oculomotility skills, and stereopsis. None of the children manifested ocular disease, known seizure disorders, or dysmorphic features. Their developmental levels ranged from average intelligence to severely retarded. Binocular visual acuity was measured with the acuity card procedure. Monocular visual acuity was not obtained. Refractive errors ranged from -4.25 to +3.25 D; the median was plano with the near retinoscopy technique. Of the 34 children, 21% were strabismic at far and 18% were strabismic at near. Lang stereo testing was attempted on all children and completed on 17. Of the 17, all but 3 exhibited 550 sec arc. Only 14.7% of the children exhibited voluntary pursuit movements, and all the children demonstrated saccadic fixations. Thirty-one children had atypical optokinetic nystagmus (OKN) responses such as delayed onset, short duration, gaze avoidance, or stereotypic behavior. Repeated testing revealed consistent visual responses on OKN and visual acuity. Given these findings, research with this population should be pursued further.

Autistic Disorder↗
PubMed1982

Antihistamines and visual function: studies on dynamic acuity and the pupillary response to light.

1 Effects of three antihistamines, triprolidine (10 mg) in a sustained release form, astemizole (10 mg) and terfenadine (60 mg), have been studied on dynamic visual acuity and on the response of the pupil to light, together with critical flicker fusion, digit symbol substitution and cancellation, and subjective assessment of mood. The study was double-blind and effects were observed from 0.5-4.0 h after ingestion. 2 Triprolidine impaired dynamic acuity and reduced the threshold for subjective fusion of a flickering light, but there were no changes with astemizole or terfenadine. The diameter of the pupil and its response to light were not changed by the drugs. 3 Performance on digit symbol substitution and cancellation was not altered by the drugs. 4 Astemizole and terfenadine are promising antihistamines for those involved in skilled activity.

Adult↗